Lloyd's auditor, the accountants Ernst & Young, warns that things will get worse before August - when the insurance market must submit its annual solvency return to the Department of Trade and Industry (DTI)
If the figures show that investors' total funds are insufficient to cover losses, the DTI may be forced to close Lloyd's down.
The solvency shortfall is caused by up to 9,000 investors - Lloyd's names - who either cannot or will not meet their share of the £8bn lost by the market over the past four years.
The accounts show that insolvent investors have current debts of £1.06bn. Against this figure, Lloyd's had liquid assets of £738m at the end of last year, a shortfall of £319m.
In addition to the current debts, a further £558m has been paid out from the market's central fund, bringing the members' total debts to £1.6bn.
The figures came only hours after the news that Sturge, one of the market's foremost managing agencies, has been unable to raise a bank loan to cover the losses on one of the syndicates of names which it operates.
The auditor's report on Lloyd's central fund accounts runs to two and half pages of closely printed type. This compares with a typical audit report which consists of half a dozen standard sentences.
The auditors say that Lloyd's finances face fundamental uncertainty. "The underwriting results to be included in the solvency test will again have deteriorated and the entire central fund will again be included in the assets available to meet the solvency requirements."
Analysts predict that Lloyd's will reveal new £1.5bn losses when it announces its figures in mid-May.
In the chairman's statement accompanying the report and accounts, David Rowland admits that Lloyd's is under strain, but insists that it remains a going concern.
Lloyd's central fund has paid out £773m over the past three years - including the payout of £558m to meet defaulting members' debts. Over that time, it has recovered less than £30m from the defaulters.
A further £460m may also have to be charged to the fund - depending on the outcome of legal actions against companies that re-insured some Lloyd's syndicates that were closed down in the early Eighties.
To replenish the fund, Lloyd's is expected to raise a levy on members in the summer. The last time this was done, in 1992, some £518m was collected. This time, the target would be to raise about £600m.
Christopher Stockwell, chairman of the Lloyd's Names Associations Working Party, said that the losses would be significantly larger than those shown in the accounts.
"There is no provision for claims against the central fund which have been started but have yet to be approved by Lloyd's council. I would expect up to £500m of such claims to be in the pipeline," he said.
9 Chatset, the independent Lloyd's analysts, last week warned that the market would need bailing out by the Bank of England if it is to pay all claims in the next 12 months - but this was denied by Lloyd's.